Copies src to dest. If src is a directory, this
method copies all its contents recursively. If dest is a
directory, copies src to dest/src.

src can be a list of files.

# Installing ruby library "mylib" under the site_rubyFileUtils.rm_rsite_ruby+'/mylib',:forceFileUtils.cp_r'lib/',site_ruby+'/mylib'# Examples of copying several files to target directory.FileUtils.cp_r%w(mail.rb field.rb debug/),site_ruby+'/tmail'FileUtils.cp_rDir.glob('*.rb'),'/home/aamine/lib/ruby',:noop=>true,:verbose=>true# If you want to copy all contents of a directory instead of the# directory itself, c.f. src/x -> dest/x, src/y -> dest/y,# use following code.FileUtils.cp_r'src/.','dest'# cp_r('src', 'dest') makes src/dest,# but this doesn't.